Noah Muthler took his first state standardized test in third grade at the Spring Cove Elementary School in Roaring Spring, Pa. It was a miserable experience, said his mother, Kathleen Muthler. He was a good student in a program for gifted children. But, Muthler said, “he was crying in my arms the night before the test, saying: ‘I’m not ready, Mom. They didn’t teach us everything that will be on the test.’ ” In fourth grade, he was upset the whole week before the exam. “He manifests it physically,” his mother said. “He got headaches and stomachaches. He would ask not to go to school.” Not a good sleeper anyway, Noah would slip downstairs after an hour tossing in bed and ask his mom to lie down with him until he fell asleep. In fifth grade, the anxiety lasted a solid month before the test. “Even after the test, he couldn’t let it go. He would wonder about questions he feared he misunderstood,” Muthler said.

So this year, Muthler is opting Noah out of the Pennsylvania System of School Assessment, using a broad religious and ethical exemption. Just knowing he won’t be taking the tests in March has put Noah in a better frame of mind about school. “The pressure is off his shoulders now,” his mother said. When he doesn’t grasp a concept immediately, he can talk it through without any panic. “He looks forward to science class and math class again,” Muthler said. “He wants to be a chemical or nuclear engineer.”

Muthler understands Noah’s distress; more mysterious is why her son Jacob, who is in eighth grade, isn’t the least bit unnerved by the same tests. He, too, is in the gifted program, but that seems to give him breezy confidence, not fear. “You would think he doesn’t even care,” Muthler marveled. “Noah has the panic and anxiety for both of them.” Nevertheless, she will opt out Jacob from the tests, too, to be consistent.

Never before has the pressure to perform on high-stakes tests been so intense or meant so much for a child’s academic future. As more school districts strive for accountability, standardized tests have proliferated. The pressure to do well on achievement tests for college is filtering its way down to lower grades, so that even third graders feel as if they are on trial. Students get the message that class work isn’t what counts, and that the standardized exam is the truer measure. Sure, you did your homework and wrote a great history report — but this test is going to find out how smart you really are. Critics argue that all this test-taking is churning out sleep-deprived, overworked, miserable children.

But some children actually do better under competitive, stressful circumstances. Why can Jacob thrive under pressure, while it undoes Noah? And how should that difference inform the way we think about high-stakes testing? An emerging field of research — and a pioneering study from Taiwan — has begun to offer some clues. Like any kind of human behavior, our response to competitive pressure is derived from a complex set of factors — how we were raised, our skills and experience, the hormones that we marinated in as fetuses. There is also a genetic component: One particular gene, referred to as the COMT gene, could to a large degree explain why one child is more prone to be a worrier, while another may be unflappable, or in the memorable phrasing of David Goldman, a geneticist at the National Institutes of Health, more of a warrior.

Understanding their propensity to become stressed and how to deal with it can help children compete. Stress turns out to be far more complicated than we’ve assumed, and far more under our control than we imagine. Unlike long-term stress, short-term stress can actually help people perform, and viewing it that way changes its effect. Even for those genetically predisposed to anxiety, the antidote isn’t necessarily less competition — it’s more competition. It just needs to be the right kind.

Every May in Taiwan, more than 200,000 ninth-grade children take the Basic Competency Test for Junior High School Students. This is not just any test. The scores will determine which high school the students are admitted to — or if they get into one at all. Only 39 percent of Taiwanese children make the cut, with the rest diverted to vocational schools or backup private schools. The test, in essence, determines the future for Taiwanese children.

The test is incredibly difficult; answering the multiple-choice questions requires knowledge of chemistry, physics, advanced algebra and geometry, and testing lasts for two days. “Many students go to cram school almost every night to study all the subjects on the test,” says Chun-Yen Chang, director of the Science Education Center at National Taiwan Normal University. “Just one or two percentage points difference will drag you from the No. 1 high school in the local region down to No. 3 or 4.”